[deliverable/linux.git] / fs / hfsplus / wrapper.c

/*
 *  linux/fs/hfsplus/wrapper.c
 *
 * Copyright (C) 2001
 * Brad Boyer (flar@allandria.com)
 * (C) 2003 Ardis Technologies <roman@ardistech.com>
 *
 * Handling of HFS wrappers around HFS+ volumes
 */

#include <linux/fs.h>
#include <linux/blkdev.h>
#include <linux/cdrom.h>
#include <linux/genhd.h>
#include <asm/unaligned.h>

#include "hfsplus_fs.h"
#include "hfsplus_raw.h"

struct hfsplus_wd {
	u32 ablk_size;
	u16 ablk_start;
	u16 embed_start;
	u16 embed_count;
};

static void hfsplus_end_io_sync(struct bio *bio, int err)
{
	if (err)
		clear_bit(BIO_UPTODATE, &bio->bi_flags);
	complete(bio->bi_private);
}

int hfsplus_submit_bio(struct block_device *bdev, sector_t sector,
		void *data, int rw)
{
	DECLARE_COMPLETION_ONSTACK(wait);
	struct bio *bio;
	int ret = 0;

	bio = bio_alloc(GFP_NOIO, 1);
	bio->bi_sector = sector;
	bio->bi_bdev = bdev;
	bio->bi_end_io = hfsplus_end_io_sync;
	bio->bi_private = &wait;

	/*
	 * We always submit one sector at a time, so bio_add_page must not fail.
	 */
	if (bio_add_page(bio, virt_to_page(data), HFSPLUS_SECTOR_SIZE,
			 offset_in_page(data)) != HFSPLUS_SECTOR_SIZE)
		BUG();

	submit_bio(rw, bio);
	wait_for_completion(&wait);

	if (!bio_flagged(bio, BIO_UPTODATE))
		ret = -EIO;

	bio_put(bio);
	return ret;
}

static int hfsplus_read_mdb(void *bufptr, struct hfsplus_wd *wd)
{
	u32 extent;
	u16 attrib;
	__be16 sig;

	sig = *(__be16 *)(bufptr + HFSP_WRAPOFF_EMBEDSIG);
	if (sig != cpu_to_be16(HFSPLUS_VOLHEAD_SIG) &&
	    sig != cpu_to_be16(HFSPLUS_VOLHEAD_SIGX))
		return 0;

	attrib = be16_to_cpu(*(__be16 *)(bufptr + HFSP_WRAPOFF_ATTRIB));
	if (!(attrib & HFSP_WRAP_ATTRIB_SLOCK) ||
	   !(attrib & HFSP_WRAP_ATTRIB_SPARED))
		return 0;

	wd->ablk_size =
		be32_to_cpu(*(__be32 *)(bufptr + HFSP_WRAPOFF_ABLKSIZE));
	if (wd->ablk_size < HFSPLUS_SECTOR_SIZE)
		return 0;
	if (wd->ablk_size % HFSPLUS_SECTOR_SIZE)
		return 0;
	wd->ablk_start =
		be16_to_cpu(*(__be16 *)(bufptr + HFSP_WRAPOFF_ABLKSTART));

	extent = get_unaligned_be32(bufptr + HFSP_WRAPOFF_EMBEDEXT);
	wd->embed_start = (extent >> 16) & 0xFFFF;
	wd->embed_count = extent & 0xFFFF;

	return 1;
}

static int hfsplus_get_last_session(struct super_block *sb,
				    sector_t *start, sector_t *size)
{
	struct cdrom_multisession ms_info;
	struct cdrom_tocentry te;
	int res;

	/* default values */
	*start = 0;
	*size = sb->s_bdev->bd_inode->i_size >> 9;

	if (HFSPLUS_SB(sb)->session >= 0) {
		te.cdte_track = HFSPLUS_SB(sb)->session;
		te.cdte_format = CDROM_LBA;
		res = ioctl_by_bdev(sb->s_bdev,
			CDROMREADTOCENTRY, (unsigned long)&te);
		if (!res && (te.cdte_ctrl & CDROM_DATA_TRACK) == 4) {
			*start = (sector_t)te.cdte_addr.lba << 2;
			return 0;
		}
		printk(KERN_ERR "hfs: invalid session number or type of track\n");
		return -EINVAL;
	}
	ms_info.addr_format = CDROM_LBA;
	res = ioctl_by_bdev(sb->s_bdev, CDROMMULTISESSION,
		(unsigned long)&ms_info);
	if (!res && ms_info.xa_flag)
		*start = (sector_t)ms_info.addr.lba << 2;
	return 0;
}

/* Find the volume header and fill in some minimum bits in superblock */
/* Takes in super block, returns true if good data read */
int hfsplus_read_wrapper(struct super_block *sb)
{
	struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
	struct hfsplus_wd wd;
	sector_t part_start, part_size;
	u32 blocksize;
	int error = 0;

	error = -EINVAL;
	blocksize = sb_min_blocksize(sb, HFSPLUS_SECTOR_SIZE);
	if (!blocksize)
		goto out;

	if (hfsplus_get_last_session(sb, &part_start, &part_size))
		goto out;
	if ((u64)part_start + part_size > 0x100000000ULL) {
		pr_err("hfs: volumes larger than 2TB are not supported yet\n");
		goto out;
	}

	error = -ENOMEM;
	sbi->s_vhdr = kmalloc(HFSPLUS_SECTOR_SIZE, GFP_KERNEL);
	if (!sbi->s_vhdr)
		goto out;
	sbi->s_backup_vhdr = kmalloc(HFSPLUS_SECTOR_SIZE, GFP_KERNEL);
	if (!sbi->s_backup_vhdr)
		goto out_free_vhdr;

reread:
	error = hfsplus_submit_bio(sb->s_bdev,
				   part_start + HFSPLUS_VOLHEAD_SECTOR,
				   sbi->s_vhdr, READ);
	if (error)
		goto out_free_backup_vhdr;

	error = -EINVAL;
	switch (sbi->s_vhdr->signature) {
	case cpu_to_be16(HFSPLUS_VOLHEAD_SIGX):
		set_bit(HFSPLUS_SB_HFSX, &sbi->flags);
		/*FALLTHRU*/
	case cpu_to_be16(HFSPLUS_VOLHEAD_SIG):
		break;
	case cpu_to_be16(HFSP_WRAP_MAGIC):
		if (!hfsplus_read_mdb(sbi->s_vhdr, &wd))
			goto out_free_backup_vhdr;
		wd.ablk_size >>= HFSPLUS_SECTOR_SHIFT;
		part_start += wd.ablk_start + wd.embed_start * wd.ablk_size;
		part_size = wd.embed_count * wd.ablk_size;
		goto reread;
	default:
		/*
		 * Check for a partition block.
		 *
		 * (should do this only for cdrom/loop though)
		 */
		if (hfs_part_find(sb, &part_start, &part_size))
			goto out_free_backup_vhdr;
		goto reread;
	}

	error = hfsplus_submit_bio(sb->s_bdev,
				   part_start + part_size - 2,
				   sbi->s_backup_vhdr, READ);
	if (error)
		goto out_free_backup_vhdr;

	error = -EINVAL;
	if (sbi->s_backup_vhdr->signature != sbi->s_vhdr->signature) {
		printk(KERN_WARNING
			"hfs: invalid secondary volume header\n");
		goto out_free_backup_vhdr;
	}

	blocksize = be32_to_cpu(sbi->s_vhdr->blocksize);

	/*
	 * Block size must be at least as large as a sector and a multiple of 2.
	 */
	if (blocksize < HFSPLUS_SECTOR_SIZE || ((blocksize - 1) & blocksize))
		goto out_free_backup_vhdr;
	sbi->alloc_blksz = blocksize;
	sbi->alloc_blksz_shift = 0;
	while ((blocksize >>= 1) != 0)
		sbi->alloc_blksz_shift++;
	blocksize = min(sbi->alloc_blksz, (u32)PAGE_SIZE);

	/*
	 * Align block size to block offset.
	 */
	while (part_start & ((blocksize >> HFSPLUS_SECTOR_SHIFT) - 1))
		blocksize >>= 1;

	if (sb_set_blocksize(sb, blocksize) != blocksize) {
		printk(KERN_ERR "hfs: unable to set blocksize to %u!\n",
			blocksize);
		goto out_free_backup_vhdr;
	}

	sbi->blockoffset =
		part_start >> (sb->s_blocksize_bits - HFSPLUS_SECTOR_SHIFT);
	sbi->part_start = part_start;
	sbi->sect_count = part_size;
	sbi->fs_shift = sbi->alloc_blksz_shift - sb->s_blocksize_bits;
	return 0;

out_free_backup_vhdr:
	kfree(sbi->s_backup_vhdr);
out_free_vhdr:
	kfree(sbi->s_vhdr);
out:
	return error;
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/fs/hfsplus/wrapper.c
	3	*
	4	* Copyright (C) 2001
	5	* Brad Boyer (flar@allandria.com)
	6	* (C) 2003 Ardis Technologies <roman@ardistech.com>
	7	*
	8	* Handling of HFS wrappers around HFS+ volumes
	9	*/
	10
	11	#include <linux/fs.h>
	12	#include <linux/blkdev.h>
	13	#include <linux/cdrom.h>
	14	#include <linux/genhd.h>
1da177e4 LT	15	#include <asm/unaligned.h>
	16
	17	#include "hfsplus_fs.h"
	18	#include "hfsplus_raw.h"
	19
	20	struct hfsplus_wd {
	21	u32 ablk_size;
	22	u16 ablk_start;
	23	u16 embed_start;
	24	u16 embed_count;
	25	};
	26
52399b17 CH	27	static void hfsplus_end_io_sync(struct bio *bio, int err)
	28	{
	29	if (err)
	30	clear_bit(BIO_UPTODATE, &bio->bi_flags);
	31	complete(bio->bi_private);
	32	}
	33
	34	int hfsplus_submit_bio(struct block_device *bdev, sector_t sector,
	35	void *data, int rw)
	36	{
	37	DECLARE_COMPLETION_ONSTACK(wait);
	38	struct bio *bio;
50176dde	39	int ret = 0;
52399b17 CH	40
	41	bio = bio_alloc(GFP_NOIO, 1);
	42	bio->bi_sector = sector;
	43	bio->bi_bdev = bdev;
	44	bio->bi_end_io = hfsplus_end_io_sync;
	45	bio->bi_private = &wait;
	46
	47	/*
	48	* We always submit one sector at a time, so bio_add_page must not fail.
	49	*/
	50	if (bio_add_page(bio, virt_to_page(data), HFSPLUS_SECTOR_SIZE,
	51	offset_in_page(data)) != HFSPLUS_SECTOR_SIZE)
	52	BUG();
	53
	54	submit_bio(rw, bio);
	55	wait_for_completion(&wait);
	56
	57	if (!bio_flagged(bio, BIO_UPTODATE))
50176dde SF	58	ret = -EIO;
	59
	60	bio_put(bio);
	61	return ret;
52399b17 CH	62	}
52399b17 CH	63
1da177e4 LT	64	static int hfsplus_read_mdb(void bufptr, struct hfsplus_wd wd)
	65	{
	66	u32 extent;
	67	u16 attrib;
2179d372	68	__be16 sig;
1da177e4	69
2179d372 DE	70	sig = (__be16 )(bufptr + HFSP_WRAPOFF_EMBEDSIG);
	71	if (sig != cpu_to_be16(HFSPLUS_VOLHEAD_SIG) &&
	72	sig != cpu_to_be16(HFSPLUS_VOLHEAD_SIGX))
1da177e4 LT	73	return 0;
	74
	75	attrib = be16_to_cpu((__be16 )(bufptr + HFSP_WRAPOFF_ATTRIB));
	76	if (!(attrib & HFSP_WRAP_ATTRIB_SLOCK) \|\|
	77	!(attrib & HFSP_WRAP_ATTRIB_SPARED))
	78	return 0;
	79
2753cc28 AS	80	wd->ablk_size =
2753cc28 AS	81	be32_to_cpu((__be32 )(bufptr + HFSP_WRAPOFF_ABLKSIZE));
1da177e4 LT	82	if (wd->ablk_size < HFSPLUS_SECTOR_SIZE)
	83	return 0;
	84	if (wd->ablk_size % HFSPLUS_SECTOR_SIZE)
	85	return 0;
2753cc28 AS	86	wd->ablk_start =
2753cc28 AS	87	be16_to_cpu((__be16 )(bufptr + HFSP_WRAPOFF_ABLKSTART));
1da177e4	88
8b3789e5	89	extent = get_unaligned_be32(bufptr + HFSP_WRAPOFF_EMBEDEXT);
1da177e4 LT	90	wd->embed_start = (extent >> 16) & 0xFFFF;
	91	wd->embed_count = extent & 0xFFFF;
	92
	93	return 1;
	94	}
	95
	96	static int hfsplus_get_last_session(struct super_block *sb,
	97	sector_t start, sector_t size)
	98	{
	99	struct cdrom_multisession ms_info;
	100	struct cdrom_tocentry te;
	101	int res;
	102
	103	/* default values */
	104	*start = 0;
	105	*size = sb->s_bdev->bd_inode->i_size >> 9;
	106
dd73a01a CH	107	if (HFSPLUS_SB(sb)->session >= 0) {
dd73a01a CH	108	te.cdte_track = HFSPLUS_SB(sb)->session;
1da177e4	109	te.cdte_format = CDROM_LBA;
2753cc28 AS	110	res = ioctl_by_bdev(sb->s_bdev,
2753cc28 AS	111	CDROMREADTOCENTRY, (unsigned long)&te);
1da177e4 LT	112	if (!res && (te.cdte_ctrl & CDROM_DATA_TRACK) == 4) {
	113	*start = (sector_t)te.cdte_addr.lba << 2;
	114	return 0;
	115	}
634725a9	116	printk(KERN_ERR "hfs: invalid session number or type of track\n");
1da177e4 LT	117	return -EINVAL;
	118	}
	119	ms_info.addr_format = CDROM_LBA;
2753cc28 AS	120	res = ioctl_by_bdev(sb->s_bdev, CDROMMULTISESSION,
2753cc28 AS	121	(unsigned long)&ms_info);
1da177e4 LT	122	if (!res && ms_info.xa_flag)
	123	*start = (sector_t)ms_info.addr.lba << 2;
	124	return 0;
	125	}
	126
	127	/* Find the volume header and fill in some minimum bits in superblock */
	128	/* Takes in super block, returns true if good data read */
	129	int hfsplus_read_wrapper(struct super_block *sb)
	130	{
dd73a01a	131	struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
1da177e4 LT	132	struct hfsplus_wd wd;
	133	sector_t part_start, part_size;
	134	u32 blocksize;
52399b17	135	int error = 0;
1da177e4	136
52399b17	137	error = -EINVAL;
1da177e4 LT	138	blocksize = sb_min_blocksize(sb, HFSPLUS_SECTOR_SIZE);
1da177e4 LT	139	if (!blocksize)
52399b17	140	goto out;
1da177e4 LT	141
1da177e4 LT	142	if (hfsplus_get_last_session(sb, &part_start, &part_size))
52399b17	143	goto out;
5c36fe3d BH	144	if ((u64)part_start + part_size > 0x100000000ULL) {
5c36fe3d BH	145	pr_err("hfs: volumes larger than 2TB are not supported yet\n");
52399b17	146	goto out;
5c36fe3d	147	}
1da177e4	148
52399b17 CH	149	error = -ENOMEM;
	150	sbi->s_vhdr = kmalloc(HFSPLUS_SECTOR_SIZE, GFP_KERNEL);
	151	if (!sbi->s_vhdr)
	152	goto out;
	153	sbi->s_backup_vhdr = kmalloc(HFSPLUS_SECTOR_SIZE, GFP_KERNEL);
	154	if (!sbi->s_backup_vhdr)
	155	goto out_free_vhdr;
	156
	157	reread:
	158	error = hfsplus_submit_bio(sb->s_bdev,
	159	part_start + HFSPLUS_VOLHEAD_SECTOR,
	160	sbi->s_vhdr, READ);
	161	if (error)
	162	goto out_free_backup_vhdr;
	163
	164	error = -EINVAL;
	165	switch (sbi->s_vhdr->signature) {
	166	case cpu_to_be16(HFSPLUS_VOLHEAD_SIGX):
	167	set_bit(HFSPLUS_SB_HFSX, &sbi->flags);
	168	/FALLTHRU/
	169	case cpu_to_be16(HFSPLUS_VOLHEAD_SIG):
	170	break;
	171	case cpu_to_be16(HFSP_WRAP_MAGIC):
	172	if (!hfsplus_read_mdb(sbi->s_vhdr, &wd))
a1dbcef0	173	goto out_free_backup_vhdr;
52399b17 CH	174	wd.ablk_size >>= HFSPLUS_SECTOR_SHIFT;
	175	part_start += wd.ablk_start + wd.embed_start * wd.ablk_size;
	176	part_size = wd.embed_count * wd.ablk_size;
	177	goto reread;
	178	default:
	179	/*
	180	* Check for a partition block.
	181	*
1da177e4 LT	182	* (should do this only for cdrom/loop though)
	183	*/
	184	if (hfs_part_find(sb, &part_start, &part_size))
a1dbcef0	185	goto out_free_backup_vhdr;
52399b17 CH	186	goto reread;
	187	}
	188
	189	error = hfsplus_submit_bio(sb->s_bdev,
	190	part_start + part_size - 2,
	191	sbi->s_backup_vhdr, READ);
	192	if (error)
	193	goto out_free_backup_vhdr;
	194
	195	error = -EINVAL;
	196	if (sbi->s_backup_vhdr->signature != sbi->s_vhdr->signature) {
	197	printk(KERN_WARNING
	198	"hfs: invalid secondary volume header\n");
	199	goto out_free_backup_vhdr;
1da177e4 LT	200	}
1da177e4 LT	201
52399b17	202	blocksize = be32_to_cpu(sbi->s_vhdr->blocksize);
1da177e4	203
52399b17 CH	204	/*
52399b17 CH	205	* Block size must be at least as large as a sector and a multiple of 2.
1da177e4	206	*/
52399b17 CH	207	if (blocksize < HFSPLUS_SECTOR_SIZE \|\| ((blocksize - 1) & blocksize))
52399b17 CH	208	goto out_free_backup_vhdr;
dd73a01a CH	209	sbi->alloc_blksz = blocksize;
dd73a01a CH	210	sbi->alloc_blksz_shift = 0;
1da177e4	211	while ((blocksize >>= 1) != 0)
dd73a01a CH	212	sbi->alloc_blksz_shift++;
dd73a01a CH	213	blocksize = min(sbi->alloc_blksz, (u32)PAGE_SIZE);
1da177e4	214
52399b17 CH	215	/*
	216	* Align block size to block offset.
	217	*/
1da177e4 LT	218	while (part_start & ((blocksize >> HFSPLUS_SECTOR_SHIFT) - 1))
	219	blocksize >>= 1;
	220
	221	if (sb_set_blocksize(sb, blocksize) != blocksize) {
2753cc28 AS	222	printk(KERN_ERR "hfs: unable to set blocksize to %u!\n",
2753cc28 AS	223	blocksize);
52399b17	224	goto out_free_backup_vhdr;
1da177e4 LT	225	}
1da177e4 LT	226
dd73a01a CH	227	sbi->blockoffset =
dd73a01a CH	228	part_start >> (sb->s_blocksize_bits - HFSPLUS_SECTOR_SHIFT);
52399b17	229	sbi->part_start = part_start;
dd73a01a CH	230	sbi->sect_count = part_size;
dd73a01a CH	231	sbi->fs_shift = sbi->alloc_blksz_shift - sb->s_blocksize_bits;
1da177e4	232	return 0;
52399b17 CH	233
	234	out_free_backup_vhdr:
	235	kfree(sbi->s_backup_vhdr);
	236	out_free_vhdr:
	237	kfree(sbi->s_vhdr);
	238	out:
	239	return error;
1da177e4	240	}